agent_x - 12:54 pm on Nov 22, 2011 (gmt 0)
I can see a bit of a problem here. If you have in your htaccess a line to redirect hits to the non-www version of your site to the www version, and then some scraper site links to a non-existent page without the www, Googlebot will get a 301 response followed by a 404. This then looks like it's a problem with your site, not the external link.
Would people say it would be fine to just send any non-www hits to the home page with the www? If, say, you knew that virtually no-one is linking to anything other than your home page with valid non-www links anyway?